In course of time, first the power of the Bishop displayed itself, and then the power of the Pope. . . . St. Peter’s prerogative would remain a mere letter, till the complication of ecclesiastical matters became the cause of ascertaining it. . . . When the Church, then, was thrown upon her own resources, first local disturbances gave exercise to Bishops, and next ecumenical disturbances gave exercise to Popes; and whether communion with the Pope was necessary for Catholicity would not and could not be debated till a suspension of that communion had actually occurred. It is not a greater difficulty that St. Ignatius does not write to the Asian Greeks about Popes, than that St. Paul does not write to the Corinthians about Bishops. And it is a less difficulty that the Papal supremacy was not formally acknowledged in the second century, than that there was no formal acknowledgment on the part of the Church of the doctrine of the Holy Trinity till the fourth. No doctrine is defined till it is violated.

Thus, according to Newman, while the earliest church was living in peace and joy and harmony, there were popes and bishops, it’s just that no one could see them because no one had defined the doctrines of popes and bishops. They were “a mere letter”.

[Remember 150 ad: the church at Rome is ruled by a plurality of presbyters who quarrel about status and honor. The Shepherd of Hermas says: “They had a certain jealousy of one another over questions of preeminence and about some kind of distinction. But they are all fools to be jealous of one another regarding preeminence.”]

Leo XIII: “Not Buying Into Newman”
Leo XIII, however, was not buying into this business. In his 1896 encyclical Satis Cognitum, he pronounced just precisely how “visible” all of this was:

It was consequently provided by God that the Magisterium instituted by Jesus Christ should not end with the life of the Apostles, but that it should be perpetuated. We see it [visible, and not “a mere letter”] in truth propagated, and, as it were, delivered from hand to hand. For the Apostles consecrated bishops, and each one appointed those who were to succeed them immediately “in the ministry of the word” (from Section 8)

Similarly Sections 11 and 12:

The Supreme Authority Founded by Christ

11. The nature of this supreme authority, which all Christians are bound to obey, can be ascertained only by finding out what was the evident and positive will of Christ. Certainly Christ is a King for ever; and though invisible, He continues unto the end of time to govern and guard His church from Heaven. But since He willed that His kingdom should be visible He was obliged, when He ascended into Heaven, to designate a vice-gerent on earth. “Should anyone say that Christ is the one head and the one shepherd, the one spouse of the one Church, he does not give an adequate reply. It is clear, indeed, that Christ is the author of grace in the Sacraments of the Church; it is Christ Himself who baptizes; it is He who forgives sins; it is He who is the true priest who bath offered Himself upon the altar of the cross, and it is by His power that His body is daily consecrated upon the altar; and still, because He was not to be visibly present to all the faithful, He made choice of ministers through whom the aforesaid Sacraments should be dispensed to the faithful as said above” (cap. 74). “For the same reason, therefore, because He was about to withdraw His visible presence from the Church, it was necessary that He should appoint someone in His place, to have the charge of the Universal Church. Hence before His Ascension He said to Peter: ‘Feed my sheep’ ” (St. Thomas, Contra Gentiles, lib. iv., cap. 76).

Jesus Christ, therefore, appointed Peter to be that head of the Church; and He also determined that the authority instituted in perpetuity for the salvation of all should be inherited by His successors, in whom the same permanent authority of Peter himself should continue. And so He made that remarkable promise to Peter and to no one else: “Thou are Peter, and upon this rock I will build my church” (Matt. xvi., 18). “To Peter the Lord spoke: to one, therefore, that He might establish unity upon one” (S. Pacianus ad Sempronium, Ep. iii., n. 11). “Without any prelude He mentions St. Peter’s name and that of his father (Blessed art thou Simon, son of John) and He does not wish Him to be called any more Simon; claiming him for Himself according to His divine authority He aptly names him Peter, from petra the rock, since upon him He was about to found His Church” (S. Cyrillus Alexandrinus, In Evang. Joan., lib. ii., in cap. i., v. 42).

The Universal Jurisdiction of St. Peter
12. From this text it is clear that by the will and command of God the Church rests upon St. Peter, just as a building rests on its foundation. Now the proper nature of a foundation is to be a principle of cohesion for the various parts of the building. It must be the necessary condition of stability and strength. Remove it and the whole building falls. It is consequently the office of St. Peter to support the Church, and to guard it in all its strength and indestructible unity. How could he fulfil this office without the power of commanding, forbidding, and judging, which is properly called jurisdiction? It is only by this power of jurisdiction that nations and commonwealths are held together. A primacy of honour and the shadowy right of giving advice and admonition, which is called direction, could never secure to any society of men unity or strength.

“Does she, or doesn’t she?” Roman Catholics today want it both ways. It is “visible” and “immediate” and “universal”, “the same permanent authority of Peter” and yet at the same time it must “lay dormant until it be ascertained”. That is very clearly talking out of both sides of your mouth whatever language you are speaking.

“Don’t Fluff Me Off”
The other alternative is to say “Papal encyclicals aren’t “infallible”. But then, too, you have a later church “morphing” what it was that the earlier “church” meant at the time. Pius XII, who defined the Assumption of Mary dogma, wrote in Humani Generis that popes don’t write what they write intending that people will fluff it off:

Nor must it be thought that what is expounded in Encyclical Letters does not of itself demand consent, since in writing such Letters the Popes do not exercise the supreme power of their Teaching Authority. For these matters are taught with the ordinary teaching authority, of which it is true to say: “He who heareth you, heareth me”; and generally what is expounded and inculcated in Encyclical Letters already for other reasons appertains to Catholic doctrine. But if the Supreme Pontiffs in their official documents purposely pass judgment on a matter up to that time under dispute, it is obvious that that matter, according to the mind and will of the Pontiffs, cannot be any longer considered a question open to discussion among theologians.

But in the last 50 years, you’ve got whole centuries-worth of Roman Catholics taught (as I was taught), that Peter was the first pope, Linus the second, Cletus the third, Clement the fourth (or second, depending upon whom you read), etc. – it’s a good thing that the generation who knew this is dying off, so that Rome can now begin to perpetuate a new fiction.